Aircraft



NOV- 2, 1943- `J. w. DYER ErAL 2,333,364

i AIRCRAFT Filed July 26,' 1935 4 Sheets-Sheet l fig-z Nov. 2, 1943. J. w. DYER ETAL AIRCRAFT Filed July 26, 1935 4 Sheets-Sheet 2 Nov. 2, 1943 l .1. w. DYl-:R ETAL 2,333,364

AIRCRAFT Filed July 26, 1955 4 Sheets-Sheet 5 I J. W. DYER ETAL- Nov. 2, 19.43.

Y AIRCRAFT Filed July-26. 1935 4 heets-Sh'eet 4 chine subsequently rises.

Patented Nov. 2, 1943 UNITED 'STATI-:s PATENT OFFICE AIRCRAFT Edinburgh. Scotland In Great Britain July 27, 1934 Application July 2,6, 1935, Serial No. 33,396

22 Claims.

This invention relates to aircraft of the kind in which the lift is derived wholly or partly from an overhead rotative wing-system, commonly known as a rotor, which turns about a more or less vertical axis, and more particularly to aircraft of this kind in which the angles of incidence of the rotor blades with the air stream, i. e. the angles at which they are set to their general plane of rotation, are variable so as to enable the lifting action to be changed 110 suit the conditions of the moment. The invention also has particular reference to such aircraft in which the rotor is auto-rotative, i. e., rotated by the action of the flight wind.

In taking-oli with a machine of this character the blades are set in a position in which they have no angle of incidence or are at negative incidence, land they are then mechanically rotated, for example, by being coupled to the power unit of the machine. As soon as the pilot considers that the blades are rotating at a suill- -cient1y high speed to be capable of 'giving the required lifting action, he adjusts them until they have a positive angle oi incidence, increases the speed of the usual aiiscrew, and the ma- Clear1'y, however, before the aircraft takes off it will be necessary to .disconnect the rotor' from the power unit, since if the rotor continued to be positively driven the torque reaction between the rotor and Iusen lage would cause the latter to rotate in the opposite direction to the rotor. To enable this necessary disconnection to be effected it is the present practice tc provide a control whereby the pilot can connect and disconnect the rotor drive at will.

According to thepresent invention; therefore,

- aircraft of the kind referred to are characterized by the combination of means for varying the angles of incidence of the rotor blades and means for ensuring that the rotor shall be positively disconnected from its driving means as soon as the blades have been adjusted or set to predetermined angles of incidence. f

Expressed more specifically we provide means matically operated to render the mechanism for driving the rotor inoperative.

In a convenient construction we provide mechanism for varying the angles of incidence of the rotor blades, a control for actuating said mechanism, means for operatively interconnecting the rotor to a driving member, a clutch included in said means, a control for operating the clutch, and means for interconnecting the control for actuating the-incidence-varying mechanism to the clutch control in such a manner that when the incidence control has been adjusted into a predetermined position it automatically brings about the release of the clutch control from the position in which it has acted to engage the clutch. v

In such a construction the rotor blades are adapted to be driven by' mechanism including aclutch arranged to be operated by a control, the clutch control being associated with means which retains it in the position in which the clutch is engaged until such time as the said means is actuated to release the control under the action of. the incidence control. v

The said retaining means .may consist of a' catch or pawl adapted to engage with the clutch control when the latter is in the position in which the clutch is engaged, said catch or pawl tending to move out of engagement with theclutch control, means being provided which normally holds the catch or pawl in a position to engage the clutch control and which is interconnected with the incidence control in such a manner that when the latter is moved into a predetermined position said means is immediately moved in such a direction as to allow the catch or pawl to disengage the clutchl control. The pawl is for varying the angles of incidence ci the rotor varying the angles of incidence of the blades to'- said disconnectible means, the arrangement being such that as soon-'as the rotor blades have been adjusted or set to predetermined angles ofincidence, the said disconnectible means is auto-` ratchet in such a manner that in the event of the spring means breaking the pawl will immediately move into a'position in which it cannot engage with the ratchet. The member cooperating with the pawl may consist of a slid- Avention is' shownjfbyfway of example only, on the accompanying drawings, whereon:

Figure lis a side elevation of the front endy v of the aircraftof the type above referred to, but

with the shell orskin of the aircraft being i.

shown in dotted lines in order that the detailed construction and arrangement of;v parts'mayj-be' viewed more clearly and with the lifting or rotor blades broken for convenience of disclosure;

Fig. 1 shows diagrammatically the means for controlling the rotor drive;-

Fig. 2 is a plan view corresponding to Fig. 1*; Fig. 3 is an elevation of the friction clutch control lever; and Y f Fig. 4 is a plan view corresponding'to Fig. 3. Referring rlrst to Figs. l and 1l: A The aircraft to which the present invention is applicable may generally comprise 'the usual fuselage F, having a rotor mast rising from the top side thereof to support a rotor R, which carries the lifting and sustaining blades B;'the mast consisting of supporting struts suitably arranged and connected with the fuselage at their lower ends and supporting at their upper ends a -hollow casing |09 upon which the rotor R and its supporting axle |02 are mounted for` foreand-aft tilting movement and for lateral tilting movement, which is more particularly described and shown in our .U. S. Patents- Nos. 2,097,117 and 2,097,118, which were co-pending herewith, The fore-and-aft tilting is controlled from a hand-wheel W disposed in the cockpit of the fuselage within convenient reach of the pilot and is operatively connected with the reaches of a cable H2 which is .wound around a drum pulley |I2e.

The lateral tilting of the rotor R on the supporting structure |09 is accomplished by a 'wheel L disposed in the cockpit adjacent to the pilots seat and mounted on a shaft 8|, which has a pulley 82 over which is trained a cable 83. The cable 83 is wound about a pulley drum, not shown, to rotate a shaft '|08 to effect the lateral Y tilting of the mast |02 and the rotor R supported thereby according to the direction of rotationof the shaft |00.

The rotor hub R, on which y'the rotor vblades B are mounted, concentrically surrounds an upstanding axle |02 on the masthead |09 'in which it is journalled, as disclosed in our patents mentioned above; and the blades B are adjustable to vary their angle of incidence by rotation of a spindle 90 mounted within the axle |02 by means of a pulley drum on the lower end vthereof-.all of which is more particularly described and shown in detail in our co-pending application, Serial N. 33,398. The pulley drum |00 is 'rotated by a cable lllwound `thereon and hasits reaches led down legs vor struts of the mast into the cockpit (see Figure 1), from which they are led in opposite directions to the grooved surface of a quadrant IIS, fixed pn a rotatable spindle H1, journalled in bearings carried by the supporting structure ofthe fuselage, said spindle and quadrant being oscillatablev through the medium of the control lever C.

' shown in Figure 1, lever C may be moved to positions varying'the angle of incidence of each of the rotor blades by properly positioning the :various positions intermediate the ends of the quadrant H9, movement of the lever C in either direction transmitting a corresponding movement to the `cable H4, which will correspondingly operate thedrum |00 and the spindle 05.

Movement of lever C is also transmitted to a short-arm'lever ||0 through a link |20 through the lever 54 fixed to the shaft 29a ofthe pointer 29, of blade incident indicator 30. Fast to the pointer or its shaft 29n is a lever arm |25 to which isY attached one end of a tie-bar 3|, for

-the purpose of releasing the -manually operatable clutch 6 to disconnect the drive from a motor E or other source of power from the rotor R, when the angle of incidence of the rotor blades has been increased in a predetermined'amount.

Now, having described the general characteristics-and operation of the machine to which, as one example, the present invention is applicable, the latter will now be described in detail.

Accordingto the present invention, the rotor R is adapted to be driven from the engine E (which may also actuate the screw propeller P), for the purpose of running up the motor R to effect direct take-olf while the craft is stationary on the ground and while,` the blades B are in negative or no-lift position; and-further, interconnecting means is provided between the blade incidence varying means and the engine drive tov is driven from the engine in the manner de-v scribed in another of our co-pending applications Serial No. 33,397, through an eccentrically arranged starter pinion o, the spindle s of which.

is connected by a universal joint to a telescopic rotor drive shaft 2, the lower end of the latter being connected by a universal joint 3 to the output shaft I of a bevel gear box 5. y 'I'he input shaft (not shown) of the bevel gear box is connected to one of the elements of a friction clutch 6, the other element of which is connected to the-tailshaft 0 of the engine E through a tubular shaft 1, in which one end of the tailshaft 0 is slidable to connect and disconnect said shafts through the medium of a dog-clutch D, the. adjacent end of the shaft 0 being provided with one element of dog clutch and the other being on the tubular take-ofi' shaft The dogclutch is biased by spring 9 to be normally disengaged but is lengageable by means of a -clutch lever 0 adapted to slide the'shaft 0 in both directions to engage and disengage the dog-clutch. The control memberM for engaging the starter pinion `with its cooperating gear wheel on the rotor hub Ralso acts to control the engagement and disengagementof the said dog-clutch. the arrangement being fullylfdescribed in thegspecincation of the above mentioned no-pending patent application Ser, No..`33,391. The drive from the engineE to the ,rotor-hub I?.V is`thus trans- V- mitted through the dog-clutch, shafts 0 and 1,

friction clutch 5, gear box 5, shaft 2, spindle s and pinion o.

The friction clutch 5 is actuated by a lever I fast on the rocker-shaft 6* which, through the usual construction not shown, moves the clutch cone or sliding part b in to and out of engagement with the clutch head 5c. Todistal end of the lever Il is connected to the upper end of a rod II and the lower end of said rod is con nected to one arm of a bell-crank lever I2 pivoted on a bracket I3' carried by the fuselage structure. 'I'he lever I5 is biassed in the direction in which the clutch will be disengaged by means of a tension Spring I4 andnis pulled into the clutch-engaging position by a pull-rod I5 connected to the other arm of the bell-crank lever I2 through the spring-coupling I6, which acts to prevent harshness of engagement of the clutch elements.

Referring now to Figs. 3 and 4, the other 'end of the rod I5 is connected to a ratchet member' I'I to which a hand lever IIA, disposed within reach of the pilot, is connected. Said member is pivoted at I8 between two supporting plates I9 and is provided at one end with ratchet teeth which are adapted to be engaged when required by a pawl 2| loosely carried by a pivot pin 22 engaging an elongated slot 23 in Vthe pawl.

When thefriction clutch 5 (Fig. 1) is disengaged, the lever IIA, ratchet I'I' and pawl 2l are in the positions shown in full in'Flg. 3. The spring 24 tends to hold the pawl in this position because of the flat lower face of the pawl and in these conditions a bar 25, slidable between 'the plates I8, is free to slide from the position shown'in full lines into the position shown in pin 22 and the corner 24 of the pawl is in contact with the sliding bar 25. Therefore, since the pawl cannot reverse its motion it arrests the return movement of the ratchet and so holds broken lines and vice versa. By means hereinafter described it is so arranged that when 'the incidence control lever C, described in the speciiication of another of our co-pending applications Serial No.Y 33,398, is in the position corresponding to negative incidence of the rotor blades B (i. e. left-hand position as viewed in Fig. l), the sliding bar 25 is in the position shown in full lines, with the corner 26 of the pawl 2I just clear of or only lightly touching the surface' 25a of the bar, In order to engage the clutch, the pilot raises the' lever I'IA, which causes the ratchet member I1 and the rod I5 to move towards the positions shown by the broken lines against the 'tension or bias of the spring I4, or equivalent means which maintains the clutch E normally disengaged. At the same time, the ratchet 20 bears on and presses down the pawl 2I against the resistance of the 'spring 24 and, by virtue of the shape and disposition of the slot 23 inthe pawl, the resultant movement of the pawl is virtually a. rotation about its corner 25 in a clockwisedirection. AIt will be 'obvious that after a certain amount of m'ovement of the pawl in this direction the ratchet ment past the corner 28 of the pawl without interference but for the spring 24 which lightly but continually presses the pawl against the longer sloping faces of the ratchet teeth. When the clutch 5 is fully engaged, the pilot releases the lever ITA which tends to resume its original position and so to reverse all the movements de scribed above. The shorter face of one of the ratchet teeth 28, however, engages with the underside of the corner 28 of -the pawl 2I and so tends to turn the pawl in a counter-clockwise direction, but is unable to do so as the bot-torn of the slot 23 is in engagement with the fixed the clutch'in engagement. In order to release the clutch 5 the sliding bar 25 is -moved to the- ZIA in Fig. 3. 'I'he levers I'I and I'IA and theV rod I5 can then resume their original positions under the influence of the spring I4v (Figs. 1 and 2) and the clutch 5 is disengaged.

In the event of the spring 24 breaking, the pawl 2|' would drop downwards until the top o! the slot 23 engaged with the 'pin 22 and in this position, which is shown in dotted lines at 2IB in Fig. 3, the pawl could not operate to hold the clutch 6 in engagement, nor could it restrict the movement of the sliding bar 25. This arrangement is important since, as described hereinafter, the bar`25 is coupled to the incidence control mechanism with the -free movement of which there must b'e no interference.

In Fig. l, there is shown, a pointer 29 working in conjunction with a scale 28 marked w1th` divisions corresponding to the angles of incidence of the rotor blades B. As also disclosedV in the specification of our other co-pending patent application Serial No. 33,398, the'said pointer 28 is connected by link |28 to the control C which the pilot operates to vary the angles of incidence of the rotor blades, so lthat the indicator must move in conjunction wit-h the said control.A The sliding bar 25 is connected to one end of an adjustable composite tie-bar 3l 'through the lower part of a spring-loaded claw coupling 52 which can be pulled upwards relatively to its upper part in opposition to the spring t0 lift the sliding bar 25. The said coupling, however, acts as an integral part of the bar 3l when the latter is pulled upwards as described hereinafter'. The upper end of the tie-bar 3I is connected to a llaterally extending arm I 25 xed to the axisl can be lifted, as mentioned above, without disturbing the partconnected to the bar 3l. A rest 33 is provided for supporting the lever I'IA when the latter is in its inoperative position.

Whilst the aircraft is on the ground the rotor blades B are normally kept at their negative angles of incidence by suitably positioning the control lever C, so that thev aircraft can be left stand.- ing quite safely even in a strong wind suilicient to cause the rotor blades to rotate, since, as the blades are atv negative incidence, there is no danger of the blades being blown upwards or of the aircraft being lifted by the wind. Before the engine E is started, 'the pilot engages the aforesaid dog-clutch D and the starter pinion 0 by saar-,31,34

Xandvcthel engine is zthenacceierated-until'the.

rotor. xattains .a x. predetermined I' revolutions per minute .fasfwouldlift thefmachine directly from the@ ground should l.the blades be movedrfto' apositiYe angle-of incidence. we :"if', During'nthe upward movement of the hand. leven] 1A, the -corner 28 on the pawl 2lv will have engedz-behind `one .otxthe `teeth `2li on the ratchet. member |1,thereby. acting-'to hold the f lever; ;I` 1A'. in 'the' position in which the friction clutchfis-engaged. f4 y i Now, with the parts as described fand the speed of; .Y rotation :ofl the. rotor R'being='such as will lift the machine for direct 'take-oifpthe pilot pulls" backfthe control lever. C for .varying the `angles of Y incidence of the rotorblades -B from-its original negative 1 incidence position .intof the position uin' 1 whichlthe Yblades willxbein' theinmaximu'm posil tive incidence positions and, atorabout the same course," i'moves in unison 1 withthefl said control lever Cbyreason ofthe connecting linkl i2!) andi-- in doing so, pulls upV the'fslid barf`25 into the position v(shown in Fig. 3 inlbroken lines) in which thecorner26 of the'ipawl is forced by the action y:ofthe spring-loaded' lever 'HA under the shoulder :21; on the'bar15, thelfpawly then being in.the;position shown in' dotted lines `ZIA with itsrcorner28 clear of the ratchet `teeth 20 and the :leverf l'l.Er drops ato its full-linep'osition shown in Figures 1,`1EL and 3. This movement of the bari. 25 Etakes place whenthe incidence control iever'Clhas moved a predetermined distance towardstlie lposition of maximumiincidence, the distance being variable by making the composite tie` bary 3l adjustable. By ther Vdropping of the lever Il, the friction' clutch 6 is'th'en` disengaged under -the action of the tension spring I4 and thelever I0, link ll,bellcrank I2, connecting rod1|5,1.the ratchet member I1 land the leverA i HA are `all returned to their original positions.

In. thermeantime, the pawl 2l will then return to its original position, shown ln full lines, underthe inuence of the spring 2l', leaving an unrestricted passage ior the'slide bar 25 when it is forced downwards' as the incidence control lever is returned to the position corresponding to negative incidence on the rotor blades.

Not only is the friction'clutch 8 disengaged when the incidence control has reached the predetermined incidence position in its movement towards positive incidence but, at about the same time as the clutch 6 is disengaged, the said dog-clutch D and the starter pinion o are operation of the control member M being' actuated by linkl 120, leverv arm 53, and link 38. There is thus a double safeguard against the rotor R. being driven by the engine after the rotor blades have passed a selected point in their movement froml negative to positive incidence for `varyimgfthe ing-on is considerably simpliiied. Sp long as M l ioeldenceoeotrorievxzivffihmf' incidence side of the point at'whiclitlie e s is tripped' tnecliitcn et bythe pawrziff" 'rh 'l 1.l mana 'craft-'of'tii life.

for drivingltherfo'lto I varying means i'oiibr tween the rotbrfaridzits vupon."V

trol from the .determined 'angie of incidence? 'anisrn for varying the' a position ast aililt'or.

engage the clute 3. lIn an aircraft kind to',`

anismwffor` ,varyinhthe' angles A oi vincidence .-oi the rotor bladef`s `,1la control yfoi-...actuating said:

mechanism, means,,for.ioperatlvelyginterconnectalso-brought to their inoperative positions by in'g the rotorv toQa divingfmember. aclutch included insal'd mean`s,.a control for Aoperating the clutch,means`y forliv retaining said clutch control in a positionin .whlch'the clutch is engaged, andmeans for,releasing'saidA clutch control retaining means actiiatedby said incidence control.

4Q In an aircraitof the kind referred to, mechanism for lvarying .the angies. of='jincidence of the rotor blades.' a controlfor-actuating said mechanism, meansI for operatively interconnecting the rotor toy a ldriving member, a clutch included in said means, a control for operating the clutch, means for locking said `clutch control 'in a position in `which the clutch is engaged f and means for releasing said locking means under the control oi the incidence control.

5. Inan aircraft of the kind referred to, mechanism for varying the, angles of incidence of the rotor biades,vawcontro1 for actuating said' mechanism, means foroperatively interconnecting the rotor to a drivingy member, a clutch included in said means, acontrol for operating the clutch, a catch o r pawl adapted to engage the clutch control when the latter'is in the position 'in which the clutch is engaged, said catch or pawl tending to move out oi.' engagement with the clutch control, and-means `which normally holds the catch or pawl in a position to engage the clutch control, said last ynamed means being j the rotor to a a clutch included men' in when.. ams este@ .we

aseasu in said means, a control for operating the clutch, and a pawl which is. normally forced into a position in which it can engage a ratchet associated with the clutch control under the action of spring means, said pawl being supported normally in its ratchet-engaging position by a member which when moved in one direction by the movement of the incidence controlallows the pawl to move into a position in which it can no longer engage the ratchet associated with the clutch control until said member has been returned into its original position.

1. A combination as claimed in claim 6, in which the pawl is mounted for movement towards and away from the ratchet in such a manner that in the event of the spring means breaking the pawl will immediately move into a position in which it cannot engage the ratchet.

8. A combination as claimed in claim 6, in

'which the member' co-operating with the pawl consists of a slidabl'e bar which is coupled to means operatively connecting-it to the incidencev control through a member which allows the said bar to be moved so as to render, the pawl inoperative without disturbing the incidence control.

9. A combination as' claimed in claim 2, in which there is included a spring-coupling inthe clutch control to prevent harshness of engagement of the clutch.

10. Inv an aircraft of the kind referred to, the

combination comprising mechanism for varying been adjusted into predetermined angles of incidence the said disconnecting means is operated. to render the driving mechanism ineiiective to drive the rotor.

14. In an aircraft, a sustaining rotor including autorotatanie blades and means for varying the pitch between a substantially rio-lift pitch and a positive pitch, driving means ior overspeeding the rotor prior to take-oli with the blades in nolift pitch, means for disconnecting the driving means, means ior progressively and controllably raising theY blade pitch for direct take-off, and means effecting a sequential operation of the last two mentioned means.

15. In an aiciart of thekind described, a sustaining rotor having autorotative rotor blades,.

mechanism including a clutch for driving said blades during the running-up period, mechanism for varying tne pitch-angles of the blades, a control for operating said clutch, means for holding the clutch control in the clutch-engaging position, andmeans operatively interconnecting the pitchlangle changing mechanism and the clutch control 'so that/operation of the pitch angle changing mechanism to increase the pitch angles will bring about the return of said clutch control to the position in which said clutch is disengaged.

16. In an aircraft as claimed in claim 15, wherein the mechanism interconnecting the pitch angle changing mechanism and the clutch control includes a spring pressed member.

17. In an aircraft as claimed in claim 15,

wherein the mechanism interconnecting the pitch angle changing mechanism and the clutch control includes a catch adapted to engage with the clutch control when the latter is in the clutchfor varying the angles of incidence of the rotor blades, mechanism for driving the rotor including a plurality of disconnectible means, and means connecting the incidence-varying means andthe means for driving the rotor and arranged to break the connections between the rotor and its'driving means automatically as soon as the blades have been adjusted or set to predetermined angles of incidence.

l2. An aircraft of the kind in which the lift is derived wholly or partly from an overhead rotative wing whereby system or rotor, comprising in combination, means for driving the rotor, means for varying the angles of incidence of the rotor blades, and means operatively connecting the said'angle-varying means and the means for driving the rotor'and operable inresponse to movement of the blades by said anglevarying means to predetermined angles of incidence to disconnect the rotor from its driving means( v 13. In an aircraft of the kind referred to, means for varying the angles of incidence of the rotor blades, mechanism for driving the rotor, means for disconnecting said mechanism from the rotor, and control means connected with said incidencevarying means and for said disconnecting means operated by said angle varying means to actuate said disconnecting means in response to a given degree of movement of the angle varying means corresponding to a predetermined angle of incidence,=whereby as soon as the rotor blades have engaging position and wherein means are provided for holding the catch in a position to engage the clutch control, said, means having to be operated before the clutch control can be released.

18. In an aircraft as claimed in claim 15,

wherein the mechanism interconnecting the pitch angle changing mechanism and the clutch` lcontrol includes a member whichwhen removed timed.

A19. In an aircraft of the kind described, a rotor having variable incidence blades, means for varying the incidence of saidblades, and a control therefor, a power drive for said rotor, disconnect- 2o. 1n an aircraft of the kind described, a

sustaining rotor comprising auto-rotative and incidence variable Wings or blades, diseonnectable means for driving the rotor including a clutch, mechanical means for changing the pitch-an`gle of the rotor blades, including a device operative to eiect an increase of blade pitch in a predetermined-timed relation with the disengagement inicombmauon a rotor, blades connected with the rotor, means for driving the rotqiyemeans Ai'Qr varying the vangles` of incidence 0 1' hjrgt'r varying means and the means forklrivingthe rotuf to disconnect the rotor `troni said'fgriving means, in responseto movement;` ofls d"a.ng;le 

